Amine functionality is catalytically active towards silanol condensation. If an aminofunctional siloxane is prepared with an appreciable silanol content, the viscosity of the polymer will tend to rise as the silanol groups condense to form siloxane bonds under the influence of the amine functionality.
EP-B-757074 describes a process for stabilising the viscosity of siloxane polymer formed by condensation polymerisation which process comprises adding a substituted or unsubstituted alcohol to organo-silicon compounds used to produce the siloxane polymer by condensation polymerisation, the alcohol being of the general formula R′OH, wherein R′ is a substituted or unsubstituted alkyl group of from 4 to 30 carbon atoms.
U.S. Pat. No. 3,575,917 describes stabilizing against gelation a mixture of an organopolysiloxane and an organometallic curing catalyst which comprises incorporating in said mixture from 0.1 to 0.3% of an organic silane of the formula (ZAlk)zSi(OX)4−z, in which Z is hydrogen, amino, N-beta-aminoethyl, 1,2-epoxy or glycidoxy; Alk is a 2-6C bivalent or trivalent hydrocarbon radical; X is 1-10C alkyl, aryl, aralkyl or alkaryl; and z=1-3; and sufficient amine to maintain the pH at 7 to 9.